Dipper door brake assembly



June 24, 1958 J. c. THOMPSON DIPPER DOOR BRAKE ASSEMBLY 2 Sheets-Sheet 1 Filed April 20, 1956 FIG. .1.

INVENTOR. z/flMES C. THOMPSON ym Emma/r: v$wuz2m 4 7702 NE Y5.

June 24, 1958 J. c. THOMPSON- DIPPER DOOR BRAKE ASSEMBLY Filed April 20, 1956 2 Sheets-Sheet 2 IN VEN TOR JQMES c. THOMPSOM ATTOEA/E Y5.

United States Patent DIPPER noon BRAKE ASSEMBLY James C. Thompson, Middlesboro, Ky.

Application April 20, 1956, Serial No. 579,492 2 Claims. (Cl. 214-146) This invention relates to power shovels, and more particularly to snubbing or braking means for retarding the swinging movement of the dipper door of a power shovel.

A main object of the invention is to provide a novel and improved brake assembly for retarding the swinging movement of the dipper door of a power shovel, said assembly being simple in construction, being easy to install, and involving relatively inexpensive components.

A further object of the invention is to provide an improved retarding brake assembly for the swinging" dipper door of a power shovel, said assembly being relatively compact in size, being durable in construction, and being easy to adjust to provide a desired snubbing or retardin action for the door with which it is associated.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure 1 is a fragmentary side elevational view of a portion of the dipper of a power shovel having a dipper door hinged thereto and provided with brake means constructed in accordance with the present invention.

Figure 2 is a view showing the same structure as Figure 1 but with the dipper door in its opened position.

Figure 3 is an enlarged elevational view, with a part thereof broken away, of a brake assembly employed in Figures 1 and 2.

Figure 4 is a vertical cross sectional view taken on the line 4--4 of Figure 3.

Figure 5 is a perspective view of the inner abutment plate employed in the brake assembly of Figures 3 and 4.

Referring to the drawings, 11 generally designates a conventional power shovel having the dipper 12 and having a dipper door 13 hinged thereto, by means of respec tive arms 14 provided at the opposite marginal portions of the door 13 and having arcuately curved end portions 15 extending around the corner of the dipper 12 and pivotally connected at 16 to respective flanges 17 provided on the end of the shovel 12. Thus, the door 13 is swingable downwardly from the closed position thereof shown in Figure l to the open position thereof shown in Figure 2, by the rotation of the door supporting arms 14 clockwise, as viewed in Figures 1 and 2, around their pivotal connection 16.

In accordance with the present invention, brake assemblies, designated generally at 18, may be provided on the respective arms 14 to retard the swinging movement of the door 13, to prevent unnecessary wear on the hinge pins 16 and bushings associated therewith, to reduce the likelihood of damage to the door 13 and hinge elements thereof by slamming or excessively heavy impact of the door with the shovel 12 or with other objects adjacent thereto', to prevent damage to the latch bars associated with the door and to prevent damage'to door castings, or other members of the shovel assembly which are subjected to contact with the door or are subjected to the effects of impacts or vibrations produced by the sudden contact of the door with the shovel body.

Each door brake assembly 18 comprises a main abut- 7 2 ment plate 19 which may be circular in form, as shown in Figure 5, and which is welded, or otherwise rigidly secured to the intermediate portion of the arcuate end 15 of an associated door-supporting arm 14. The abutment plate 19 is formed with a central outwardly projecting rectangular block portion 20, which may be square in shape, as shown in Figure 5. Designated at 21 is a circular plate member having a square central aperture in which the block element 20 is receivable in the manner shown in Figure 4, and rigidly secured to the periphery of the plate member 21 is a cylindrical drum 22. The plate member 21 is secured to the abutment plate 19 by means of a plurality of bolts 23 which are threadedly engaged in the plate 19, said bolts extending through the circularplate member 21 in the manner shown in Figure 4, with the plate member 19 received in the space defined between the rim of the drum 22 and the plate 21,

through hinge lugs 27, 27 provided on the end of segment and through an intervening hinge lug 28 provided on the end of the band segment 24, the lug 28 being received between the hinge lugs 27, 27, as shown in Figure 4, and being rigidly secured to the hinge pin 26 by a set screw 29 provided in the lug 28. The lower ends of the respective friction band segments 24 and 25, as viewed in Figure 3, are provided with respective aper tured flange elements 30 and 31 which oppose each other in substantially parallel relationship and which are provided with arcuate side wall elements 32 and 33, as shown in Figures 3 and 4, defining recesses at the lower ends of thefriction band segments 24 and 25. A clamping bolt 34 extends through the apertures in the respective flanges 31 and 30, the head of the bolt being received in one of said recesses and a nut 35 being threadedly engaged on the end portion of the bolt and being received in the other recess, as is clearly shown in Figure 3.

The inside surfaces of the band elements 24 and 25 are provided with respective contact shoes 37 and 38 of. suitable friction material, said contact shoes engaging the surface of the drum 22, and the frictional force exerted by the contact shoes on the drum surface being regulated by adjusting the tension on the bolt 34.

.The friction band segment 25 is provided at its upper portion, as viewed in Figure 3, with an upstanding apertured lug 39, and pivotally connected to said lug 39, 'as by a pivot pin 49, is one end of an arcuate link arm'41. The other end of the link arm is pivotally connected at 42 to an upstanding apertured lug 43 provided on the edge of the associated flange 17. Suitable brass bushings are provided in the end portions of arm 41 rot-atably receiving the pivot pins 40 and 42 to minimize wear of said pivot pins.

As will be readily apparent, when the door 13 is rotated, for example, from the closed position thereof shown in Figure 1 to the open position thereof shown in Figure 2, the arms 14 rotate clockwise, whereby the link arms 41 exert a thrust on their associated band segments 25 causing said band segments 25 and the mating band segments 24 connected thereto to rotate counterclockwise on their associated brake drums 22, as viewed in Figures 1 and 2, whereby the friction of the shoes 37 and 38 on the surface of the brake drums exerts a retarding or snubbing action, preventing the door 13 from swinging downwardly at an excessively rapid speed. The degree of retardation can be regulated by adjusting the tension of the bolts 34.

Detachably secured to the outer rim of each brake Patented June 24,. 1958 drum 22 is a circular cover plate 44, each cover plate being secured to the rim of its associated drum by a plurality of fastening bolts 45, as shown in Figure 4.

As shown in Figure ,4, the cover plates 44 are substantially greater in diameter than the 1 associated drum 22, whereby the margins oftsaid cover plates project beyond the surfaces of the drums and act as retainers for the friction band elements 24 and 25, j f

While a specific tembodiment of an improved brake assembly for the dipper door of a power shovel has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art.

Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is: r

1. Ina power shovel, a dipper having a door hinged thereto, a drum element rigidly secured to said door, a pair ofopposing arcuate friction band segments mounted on said drum element for frictionally retarded rotation thereon, means hingedly connecting said band segments together at their ends, means connecting the opposite ends of said segments'to retain said segments on said drum element, and a link member pivotally connected at one end to one of said tln'ction band segments and pivotally connected at its opposite end to said dipper at a point spaced from the hinged connection of the door thereto.

' 2. In a power shovel, a dipper having a door hinged thereto, a drum element rigidly secured to a side portion of said door at a point spaced a substantial distance from the hinged connection of the door, a pair of opposing arcuate friction band segments mounted on said drum element for frictionally retarded rotation thereon, means hingedly connecting said band segments together at their ends, means connecting the opposite ends of said segments to retain said segments on said drum element and being formed and arranged to vary the tightness of the connection, whereby to exert adjustable tension on said segments, and a link member pivotally connected at one end to one of said friction band segments and pivotally connected at its opposite end to said dipper at a point spaced from the hinged connection of the door thereto.

References Cited in the file of this patent UNITED STATES PATENTS 957,234 Menck May 10, 1 910 1,752,377 Glueck Apr. 1, 1930 1,759,846 Hendry May 27, 1930 2,160,432 Davidson May 30, 1939 2,437,749 Mallory Mar. 16, 1948 2,449,826 Van DeBoe Sept. 21, 1948 

